The invention relates to a switching device comprising an actuation member, upon whose lateral displacement at least one of several switches can be actuated and which acts upon a further switch via a ram when depressed against the force of a spring.
Such switching devices may be utilized, for example, for controlling driving motors for a table plate in an X-ray examination apparatus, in which event efficaciously the direction of actuation and the direction in which the table plate is displaced by actuation of the switching device coincide. By the actuation of the further switch, a further function can be switched, which is independent of the displacement of the table plate.
In a known switching device of the kind mentioned in the opening paragraph (used in an X-ray apparatus named "Scopomat 73" marketed by N. V. Philips' Gloeilampenfabrieken), four microswitches are arranged around the ram in a manner such that their sides provided with a switching member face the cylindrical ram, which urges against one of the switching members upon a lateral displacement of the actuation member. The volume of such a switching device can be reduced, it is true, in that the microswitches are arranged as close as possible around the switching ram, but a small displacement of the actuation member is then already sufficient to initiate a switching process. Often however, short switching paths are unfavorably for the user. In a X-ray examination apparatus, for example, in which the user generally wears lead rubber gloves and acts by his thumb upon the actuation member, the user loses, with such short switching paths, the feeling whether the switch is actuated or is not actuated. A further disadvantage is that the forces which are exerted by the user on the actuation member have to be absorbed entirely by the switches.